Object property vs. Data property

[CFGrote]

All properties in model.owl.ttl are of type owl:ObjectProperty. This causes problem in ontop because the reasoner
expects ObjectProperties to relate to objects, not Literals (xsd:string, xsd:int, xsd:date, xsd:dateTime, ...). One example is core:acquisition_date which relates to strings such as "2025-02-06^^xsd:date" and should therefore be a DataProperty, not an ObjectProperty. The same holds for numerous other properties.

[joshmoore]

Discussed today during the metadata meeting. ontop is quite strict here about relations to literals. It looks like physicalSizeX on Pixels is currently a literal but should be some type of more complex object with a unit, etc.

cc: @lubianat

[gouttegd]

It looks like physicalSizeX on Pixels is currently a literal but should be some type of more complex object with a unit

That may be the case for physicalSizeX and similar, but there are other properties in model.owl.ttl that are defined as object properties even though (IMO) it doesn’t make much sense.

For example, even core:big_endian is defined as an object property (and therefore expects to be related to objects) – I don’t think that makes sense for a boolean value. That property at least should really be a data property, not an object property. And it’s probably the case as well for core:acquisition_date, and possibly several others.